There are over 32 million WordPress publishers as of December 2010: 16 million blogs hosted on WordPress.com plus 16.7 million active installations of the WordPress.org software.

That there are more than 32 million WordPress blogs in total is impressive, but it is the world’s most popular blogging platform so the number should be high. The really amazing number here is that very close to half of those blogs are now hosted on the WordPress.com service.

Hosting half of all WordPress blogs is a huge milestone for WordPress.com.

Early in 2010 WordPress.com hosted 10 million blogs, so the rise to 16 million in less than a year is definitely a sign of rapid growth. The service launched in November of 2005.

Where the growth is coming from

You may remember that Microsoft and Automattic announced back in September last year that all Windows Live Spaces customers would be able to migrate their blogs to WordPress.com. This of course gave WordPress.com a boost, but not as big a boost as you might think. Microsoft reported late in November that half a million blogs had been migrated, and another half a million new WordPress.com blogs had been created by its Windows Live users.

The biggest key to the continued growth of WordPress.com is most likely that of cost and convenience compared to setting up your own WordPress blog at a web hosting provider. It’s just quicker and easier (and for most, free), so a lot of people looking to set up a WordPress blog will choose that option.

This doesn’t take away from the fact that Automattic has been very successful with the WordPress.com service. To have as many WordPress blogs as all other web hosting companies on the Internet combined is quite a feat.